Weed Control Guide updated for grain and forage producers

February 8, 2011

WEST LAFAYETTE, Ind. - The 2011 Weed Control Guide for Ohio and Indiana is now available to help grain producers combat some of the states' most problematic weeds.

The guide, updated annually to reflect the changing herbicide market and evolving weeds, gives producers the information they need to make informed decisions on how to control weeds. It is compiled and updated by Purdue Extension weed scientists Bill Johnson, Glenn Nice, Tom Bauman and Tom Jordan and Ohio State Extension weed scientists Mark Loux, Doug Doohan and Tony Dobbels.

"Each year we add the new herbicides that have come onto the market, and if some of the application instructions have changed, we update that information," Johnson said. "If we have a new herbicide-tolerant crop that comes onto the market, we include new information on how to use that crop for a specific system."

The guide is set up so producers can easily find specific information. In the front are sections for specific crops, and within those sections are efficacy tables. Those tables show which herbicides work best on the five or six most problematic weeds a producer might find in the fields. Johnson said this helps quickly narrow herbicide choices.

"If farmers want more information on how to use a specific herbicide or any precautions or restrictions, we have included short write-ups that follow the efficacy tables that can provide more use information," he said. "What we try to do is help growers not to have to read entire herbicide labels. They can extract the most pertinent information, and if they need a greater level of detail, they can then refer to the label."

There also is a section in the back that includes more detailed information for controlling problematic and herbicide-resistant weeds.

"Some weeds are very difficult to manage and require more information than what the efficacy tables can offer," Johnson said.

Some of the more difficult weeds include burcucumber, marestail, giant ragweed, morning glory, common lambsquarter and volunteer corn - all of which have become increasingly difficult to control with glyphosate because of resistance or emergence patterns that help them avoid glyphosate exposure.